Fallacies and Assumptions

Running head: FALLACIES AND ASSUMPTIONS

Fallacies and Assumptions

University of Phoenix Online

CSS 330 Critical Thinking and Computer Logic

May 16, 2006

Abstract

People around the world encounter logical fallacies on almost a daily basis. This paper will look at three common logical fallacies. I will define each of the three fallacies, explain its significance to Critical Thinking, and discuss its general application to Decision Making. I will also show organizational examples that illustrate each one of my chosen fallacies.

Fallacies and Assumptions

Encyclopaedia Britannica (2006) defines a fallacy in logic as “erroneous reasoning that has the appearance of soundness.” Generally, when we think about making decisions, most people believe that they are making logical decisions. Logical decisions are based on facts, rational thought and sensible reasoning. A critical thinker should be able to determine a rational decision based on facts rather than emotion or “erroneous reasoning.”

Bassham, Irwin, Nardone & Wallace (2002) say that fallacies, which are arguments that contain mistakes in reasoning, fall into two groups. The first group, fallacies of relevance, occurs because the premises are irrelevant to the conclusion. Fallacies of insufficient evidence do not provide sufficient evidence to support the conclusion even though the premises are logically relevant.

The first fallacy that I will discuss is the appeal to authority fallacy. This fallacy occurs when a person either claims to be or is presented as an authority on a specific subject and makes a claim about that subject. Since the person appears to be an authority, it is taken for granted that the claim must be true.

When a person falls prey to this fallacy, they are accepting a claim as true without there being adequate evidence to do so. More specifically, the person is accepting the claim because they erroneously believe that the person making the claim is a legitimate expert and hence that the claim is reasonable to accept (Labossiere, 1995).

Not all appeals to authority